Rotary vane-type pump structure



Oct. 12, 1965 E. c. KIEKHAEFER 3,211,103

ROTARY VANE-TYPE PUMP STRUCTURE Filed Feb. 7, 1962 INVENTOR. ELMER C. K/EKHAEFER Attorneys United States Patent 3,211,103 RQTARY VANlE-TYPE PUMP STRUCTURE Elmer C. 'Kiekhaefer, Winter Haven, Fla, assignor to Kiekhaefer Corporation, Chicago, 111., a corporation of Delaware Filed Feb. 7, 1962, Ser. No. 171,697 Claims. '(Cl. 103117) This invention relates to a rotary vane-type pump structure and particularly to an improved method of securing individual replaceable vanes to a central hub member.

Rotary hydraulic pumps or motors for moving a liquid from an inlet to an outlet have been constructed with a central rotor carrying removable vanes which project outwardly into sealing engagement with an adjacent circumferential wall of a pump housing. The rotor may be eccentrically mounted such that the vane deflection and sealing engagement with the circumferential wall varies to provide the desired pumping action and to prevent the active fluid pressure from creating leakage of the liquid past the vanes.

The continuous deformation and flexing of the vanes may, after a substantial period of use, result in a reduction in the effectiveness of the vane which should then preferably be replaced.

Generally, the renewable vanes heretofore constructed have included an enlarged hub end disposed within a correspondingly shaped socket. This results in a locking of the vane within the hub member with essentially all of the flexing immediately adjacent the periphery of the hub member. Applicant has found that the greatest number of vane failures normally occurs at this area of maximum flexing and deformation.

The present invention is particularly directed to an impeller or vane socket construction for retaining a removable vane in a pump rotor with the entrance to the socket providing controlled deformation and flexing of the individual vane. In accordance with the present invention, the opening to the socket includes a deflection control wall or surface on the trailing side of the vane. The deflection control wall is a smooth, curved surface which is spaced from the immediately adjacent portion of the vane to allow restricted and controlled flexing and deformation of the vane immediately adjacent the socket.

The socket is preferably formed with straight line surfaces to minimize and essentially eliminate the tendency for the vane member to rotate within the socket. This feature is particularly important where the material being pumped carries foreign matter which may enter between the vane and the socket and in the presence of relative movement therebetween rapidly deteriorate or destroy the vane.

The present invention provides a controlled vane deformation means to substantially decrease the fatigue of the vane member due to the flexing action adjacent the hub.

The drawing furnished illustrates the best mode presently contemplated for carrying out the invention.

In the drawing:

FIG. 1 is an axial sectional view of a rotary pump;

FIG. 2 is a side elevational view with parts of the housing broken away to more clearly illustrate the construction of the impeller hub and impeller vanes;

FIG. 3 is a perspective view of a vane shown in FIGS. 1 and 2; and

FIG. 4 is a fragmentary view of the hub and impeller illustrating a further embodiment of the invention.

Referring to the drawings and particularly to FIGS. 1 and 2, the illustrated pump includes an outer cylindrical casing 1 having axial end walls 2 and 3 secured to the opposite ends of the casing to define a pump chamber 4.

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A pump impeller shaft 5 is rotatably journaled in the end walls 2 and 3 and carries an impeller 6 constructed in accordance with the present invention. A fluid inlet 7 and a fluid outlet 8 are integrally formed with the casing 1. The pump impeller 6 rotates in a counterclockwise direction, as viewed in FIG. 1, and carries the water from the inlet 7 through the pump chamber 4 and forces it out through the outlet 8.

The impeller 6 which is constructed in accordance with the present invention generally includes a rigid central tubular hub 9 which is preferably formed of a molded, sintered or extruded metal for high strength. The hub 9 is telescoped over shaft 5 within the pump chamber 4 and is keyed thereto as by a key 10 which mates with corresponding recesses in the hub 9 and the shaft 5. The axial ends of the hub 9 are slightly spaced from the adjacent surfaces of the axial end walls 2 and 3. O-ring seals 11 are disposed between the end walls 2 and 3 and the adjacent ends of the central hub 9 to provide an effective water seal of the pump chamber 4 from the shaft journals in the end walls 2 and 3. The O-ring seals 11 are radially held in place by small corresponding. annular or circular recesses formed in the inner surfaces of the end walls 2 and 3.

Four deflectable vanes 12 are secured to the hub 9 and extend generally radially and circumferentially into engagement with the outer wall defining the pump chamber 4. The vanes 12- are equicircumferentially distributed about the hub 9 and include an enlarged base 13 disposed and secured within correspondingly spaced sockets 14. Each vane 12 is generally a tapered member decreasing in thickness from the base 13 to the outer tip. This construction is desirable in that in operation the flexure of the vanes 12 is distributed more evenly by movement thereof throughout the length of the vanes and the tendency to break down or tear adjacent the base 13 of the vane is reduced. As the shaft 5 is rotated, the vanes 12 rotate with the outer ends maintained in engagement with the wall of the pump chamber 4 and establish a seal therebetween. As a result, as the vanes 12 move past the inlet 7 the water is trapped between adjacent vanes and carried to the outlet 8.

As most clearly shown in FIG. 1, the shaft 5' is eccentrically mounted Within the cylindrical casing 1 and the pump chamber 4. The eccentricity of the mounting 5 is such that the deflection or flexure of the vanes 12 increases as the respective vanes approach the outlet 8 and is greatest immediately adajacent to the outlet. As a result the sealing effect is greatest adjacent the outlet 8 where the pressure tending to cause leakage past the vanes is the greatest.

In acordance with the embodiment of the invention shown in FIG. 1, each of the sockets 14 is generally diamond shaped and a restricted opening thereto is provided to receive a correspondingly shaped base of a vane 12. The opening to each of the sockets 14 includes rounded walls 15 and 16.

The leading wall 16 extends over and into engagement with the adjacent end or extension of the vane 12 immediately adjacent the base 13. The trailing wall 15 generally defines a spiral which extends radially and circumferentially of base 13 to provide a deflection control surface.

The walls 15 and 16 present a smooth surface immediately adjacent the vane 12 and prevent sharp edges at the point of flexure which would tend to rapidly deteriorate the efficiency and structural strength of the vane.

The deflection control surface of wall 15 is particularly important in providing a long life vane. As the deflection of a vane 12 increases, as a result of rotation within the pump chamber 4, the portion adjacent base 13 progressively moves into engagement with the wall 15 which controls the deflection pattern. Wall 15 thus establishes limited and controlled deflection with a gradual decrease in the deflection area and reduces and minimizes localized flexure in the vane.

The diamond shape of socket 14 prevents the vane 12 from pivoting within socket 14 and thereby minimizes destruction of the base portion.

In FIG. 4, a fragmentary view of the hub 17 and a vane 18 is illustrated in which a cylindrical socket 19 and cylindrical base 20 are provided on the vane. With the structure of FIG. 4, the vane 18 may pivot within the socket 19 and is not therefore as suitable for certain applications as the structure of FIGS. 1-3. The embodiment of the invention illustrated in FIG. 4 otherwise functions in the same manner as that illustrated in FIGS. 1 and 2.

The present invention provides an impeller construction having the individual vane mounted in the manner to substantially reduce the deterioration of the vanes as a result of the continuous flexing of the vanes during the operation of the pump.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. In an impeller unit for a rotary vane-type displacement pump having a pump drive shaft rotatably mounted generally eccentrically within a pump housing,

(a) a supporting hub carried by the shaft and rotating therewith, said hub having a plurality of vane sockets circumferentially distributed about the hub, and

(b) vanes of a resilient flexible material having attachment bases secured one each within the sockets and extending outwardly into engagement with the pump housing,

(c) the hub having restricted openings to the sockets through which the vanes project with the openings being each defined by a deflection control surface on the hub extending as a continuous smooth curved surface of increasing radius for a substantial portion of the hub between the adjacent sockets immediately adjacent the base of the corresponding vane, and the eccentricity of the pump housing relative to the path of the vanes serving to flex said vanes successively into contact with the corresponding control surfaces beginning at the restricted opening and moving outwardly as said hub rotates and said vanes move from the maximum spacing to the minimum spacing between the hub and the wall of the pump housing.

2. The impeller unit of claim 1 wherein each deflection control surface is generally spirally shaped and projects radially and circumferentially from the base of the corresponding vane and is of a length less than the corresponding vane whereby the outermost portion of the vane is continuously spaced from the hub and the corresponding control surface.

3. The impeller unit of claim 1 wherein said socket is rectangularly shaped to prevent pivotal movement of the vane within the socket.

4. In an impeller unit for a rotary vane-type positive displacement pump having a pump drive shaft rotatably mounted generally eccentrically within a pump housing,

(a) a supporting hub carried by the shaft and rotating therewith, said hub having a plurality of vane sockets with a restricted opening thereto circumferentially distributed about the hub, and

(b) vanes of a resilient flexible material each having a base corresponding to the vane sockets and being of a generally tapered thickness with a relatively thin tip for engaging the pump housing and a thicker root section integrally formed with the base,

(c) the restricted openings to the sockets through which the vanes project toward the housing including a deflection control surface on the hub beginning at the socket adjacent the trailing side of the vane and spanning a substantial arcuate portion of the hub between the vanes, the control surface being spaced from the corresponding vane in the unflexed state of the vane to allow controlled flexing of the vane, said vanes having a strength to resist the fluid pressures on the leading sides thereof and which would tend to flex the vanes against their corresponding control surfaces, and the eccentricity of the pumphousing relative to the path of the vanes serving to flex the vanes successively into contact with the corresponding control surfaces immediately from the restricted opening outwardly as said hub rotates and said vanes move from the maximum spacing to the minimum spacing between the hub and the Wall of the pump housing.

5. In a rotary vane-type positive displacement pump of the class described,

(a) a pump housing providing a pump chamber with spaced inlet and outlet ports and having a circumferential wall and end walls adapted to confine an impeller therein,

(b) a shaft extended through at least one of the end walls and arranged eccentrically to said circumferential wall,

(0) an impeller hub secured to the shaft and having a plurality of circumferentially distributed vane sockets within the hub with restricted socket openings extending radially and circumferentially of the hub, and

(d) impeller vanes each having a base generally corresponding to and rigidly mounted within a socket and extending outwardly through said restricted openings, said vanes being of a tapered thickness decreasing in thickness from the corresponding base to the tip,

(e) the trailing wall adjacent each socket and defining the restricted opening being shaped to create a deflection control surface spanning a substantial portion of the hub between the corresponding vane sockets for the corresponding vane, said vanes having a strength to resist the fluid pressures on the leading sides thereof and which would tend to flex the vanes against their corresponding control surfaces, and the eccentricity between the housing and the shaft serving to flex the vanes successively against the corresponding control surfaces immediately from the restricted opening outwardly as said hub rotates and said vanes move from the maximum spacing to the minimum spacing between the hub and the wall of the pump housing.

References Cited by the Examiner UNITED STATES PATENTS 2,466,440 4/49 Kiekhaefer 103-117 2,636,478 4/53 Smyser 103-140 2,636,479 4/53 Smyser 103-117 2,664,050 12/53 Abresch 103-117 2,753,809 7/56 Garrison 103-117 2,843,049 7/58 Sherwood 103-117 FOREIGN PATENTS 998,602 6/49 France.

OTHER REFERENCES Garrison, German application, 1,023,469, Jan. 30, 1958, 103-140.

KARL I. ALBRECHT, Primary Examiner.

JOSEPH H. BRANSON, JR., Examiner. 

1. IN AN IMPELLER UNIT FOR A ROTARY VANE-TYPE DISPLACEMENT PUMP HAVING A PUMP DRIVE SHAFT ROTATABLY MOUNTED GENERALLY ECCENTRICALLY WITHIN A PUMP HOUSING, (A) A SUPPORTING HUB CARRIED BY THE SHAFT AND ROTATING THEREWITH, SAID HUB HAVING A PLURALITY OF VANE SOCKETS CIRCUMFERENTIALLY DISTRIBUTED ABOUT THE HUB, AND (B) VANES OF A RESILIENT FLEXIBLE MATERIAL HAVING ATTACHMENT BASES SECURED ONE EACH WITHIN THE SOCKETS AND EXTENDING OUTWARDLY INTO ENGAGEMENT WITH THE PUMP HOUSING, (C) THE HUB HAVING RESTRICTED OPENINGS TO THE SOCKETS THROUGH WHICH THE VANES PROJECT WITH THE OPENINGS BEING EACH DEFINED BY A DEFLECTION CONTROL SURFACE ON THE HUB EXTENDING AS A CONTINUOUS SMOOTH CURVED SURFACE OF INCREASING RADIUS FOR A SUBSTANTIAL PORTION OF THE HUB BETWEEN THE ADJACENT SOCKETS IMMEDIATELY ADJACENT THE BASE OF THE CORRESPONDING VANE, AND THE ECCENTRICITY OF THE PUMP HOUSING RELATIVE TO THE PATH OF THE VANE SERVING TO FLEX SAID VANES SUCCESSIVELY INTO CONTACT WITH THE CORRESPONDING CONTROL SURFACES BEGINNING AT THE RESTRICTED OPENING AND MOVING OUTWARDLY AS SAID HUB ROTATES AND SAID VANES MOVE FROM THE MAXIMUM SPACING TO THE MINIMUM SPACING BETWEEN THE HUB AND THE WALL OF THE PUMP HOUSING. 